I'm looking at a friends DE Star wars and the trough eject coil continuously fires when powered on. He found that the coil leads had melted/broken off and so he ordered a replacement coil and powered it on. Same problem. A fuse blew and was replaced and then he swapped the coil wires and turned it back on (yikes).

So, when I checked, i found Q45 was bad which is consistent with the manual. I replaced Q45 and then fired the game up but the trough eject coil still continuously fires. I re-tested Q45 and it needed to be replaced again.

So, my question is what other components on the pcb's should I be testing/replacing. Looking at the schematic, I see the other components that are on the PPB related to this are D2, D10 and R2. Isn't there another transistor on the PPB I should be looking at. Is there a pre-driver transistor? Any other components to check on the CPU pcb?

I've been looking at the following manual on page 33 of the pdf (Page 29 of the actual manual)

https://www.ipdb.org/files/2358/Data_East_1992_Star_Wars_Manual.pdf

I measured the coil and it tests fine and also replaced the diode on the coil.

I am not that familiar with DE games and so any help is much appreciated.

Bump for the 15th

Thank you very much for your help. I had not seen those schematics yet and those are just somewhat critical I will first check the wiring to the coil as I think he had the two purple wires going to the banded side of the diode and not the brown wire.

I will then test the other parts of the circuit. I appreciate it!

Just wanted to post back on this. I tested all components in the circuit for the trough eject coil and couldn't find anything other than Q45 blown. Coil wired correctly and coil diode tests good.

However, I just found capacitor C1 on the PPB board is completely dead dry.

I will be replacing this cap and hopefully this will fix it. I will report back but any thoughts on if this will fix it?

Just to circle back to this. This ended up being a dead C1 on the PPB that was causing Q45 to go bad. Replaced it and Q45 and it works now.